In the field of printers, there is conventionally known a core holding structure in which a roll-shaped core on which a strip-shaped material such as an ink ribbon is wound is held by a rotationally driven take-up shaft.
In the conventional printers, it is desirable to hold the core and prevent any idle rotation of the core when rotating the take-up shaft and winding the strip-shaped material around the core. It is also desirable that the core can be easily detachably mounted to the take-up shaft.